Flexible metallic tubing.



W. BERRYMAN & G. GAMUS.

FLEXIBLE METALLIC TUBING.

APPLICATION FILED 111111.24, 1911.

Patented Mar.26, 1912.

JJU eJYJtOTS Waite-$56.5.

vawmwn COLUMBIA PLANUGRA. c0., WASHINGTON, U. c.

ITED STATES PATENT OFFICE.

WILLIAM-BERRYMAN AND CHARLES CAMUS, OF MIDDLESEX, ENGLAND, ASSIGNORS TO UNITED FLEXIBLE METALLIC TUBING COMPANY, LIMITED, 01? PONDERS END,

ENGLAND.

FLEXIBLE METALLIC TUBING.

Application filed March 24, 1911.

T 0 all whom, it may concern Be it known that we, WILLIAM BERRY- MAN, works manager, and CHARLES CAMUs,

engineer, both subjects of the King of Great Britain, both residing in Middlesex, England, and whose post-oflice address is care of The United Flexible Metallic Tubing Company Limited, of Ponders End, in the county of Middlesex, England, have jointly invented a certain new and useful Improvement in Flexible Metallic Tubing, of which the following is a specification.

In the specification accompanying British Patent No. 12661 of 1894: it has been proposed to construct flexible metallic tubing having an oval, polygonal or other section such that one convolution cannot revolve upon another so as to untwist the coiled tubing, rendering it unsound.

The present invention relates to an improvement in such constructions of flexible metallic tubing whereby simple profiles are imparted to the metal strip from which the tubing is formed and greater flexibility is given to the tubing owing to its being possi ble to give a limited amount of play of the one convolution upon the other in the direction of its length and also in the direction of uncoiling. However, when the torque is removed, the torsion of the tubing itself and the torsion on the packing between the interlocking edges at once causes the flexible tubing to assume its normal position. To attain these objects, a profile is given to the metal strip consisting of elements which are arranged alternately parallel with and radial to the axis of the tubing, and the fiexi ble metallic tubing is coiled in such a man ner that it is formed with a series of flats arranged around its circumference or periphery, and spirally to its axis, thus producing a flexible metallic tube of polygonal section.

The invention will be described with reference to the accompanying drawing in which Figure l is an elevation showing a portion of one form of flexible tubing with spirally arranged flat surfaces, and Fig. 2 is a section of a portion of a corrugated strip of metal of which a tube may be made according to this invention.

In order to obtain the flat surfaces in spiral relation to the axis of the tube, instead of coiling the helical strip on a cylindrical Specification of Letters Patent.

Patented Mar. 26, 1912.

Serial No. 616,754.

mandrel or on a mandrel having flat surfaces parallel to the axis thereof as has been done heretofore, the helical strip a. is coiled on a mandrel so as to acquire a series of fiat sides 7) the number of which vary according to the diameter of the tube to be manufactured but which are arranged spirally to the axis of the mandrel as indicated by the lines 0, Fig. 1. Flexible metallic tubing of this kind can be coiled in machines substantially the same as those at present in use wherein the metallic corrugated strip is coiled on a short mandrel by the aid of adjustable pressing rollers. The only alterations required in such machines is the substitution of a mandrel with spiral flats formed thereon and also that a suflicient pressure should be given to the pressing rollers to force the coils of the tube to assume the shape of such flattened spiral surfaces and so form a flexible metallic tubing having flattened surfaces around the circumference arranged spirally to the axis of the tubing.

On reference to Fig. 2 it will be seen that the profile of the metal strip a consists only of a series of elements a, a 64 parallel to the axis of the tubing and an alternate series of elements (5, (Z (Z radial to that axis, while the two lateral marginal elements a and a of the strip are bent in reverse directions and so as to be opposite respectively to the outer and inner surfaces of the strip a.

This invention can also be equally applied to tubing constructed according to the specification accompanying the U. S. application Serial No. 599211 in which the strip (a from which the tube is formed comprises one or more complete channeled corrugations such as that constituted by the elements a (Z and (Z in addition to the marginal corrugations required for interlocking the corrugated strip in each separate coil of the tubing as illustrated in Fig. 2. Its application to flexible metallic tubing of this description will result in the production of tubing in a more expeditious manner and at less expense.

Having thus described the nature of our invention and the best means we know of carrying the same into practical effect, we claim 1. A flexible metallic tubing comprising a series of convolutions of a strip of metal, which tubing has a polygonal section formed by flattened surfaces arranged around the circumference of the tubing, and spirally to the axis thereof and has a profile composed of elements alternately parallel with and radial to the said axis; substantially as herein described.

2. A flexible metallic tubing comprising a series of convolutions of a strip of metal, which tubing has a polygonal section formed by flattened surfaces arranged around the circumference of the tubing, and spirally to to the axis thereof and has a profile composed of elements alternately parallel With and radial to the said axis, and in which there are corrugations on the lateral margins of the strip for interlocking one convolution With another and complete channeled corrugations intermediate of the said marginal corrugations, substantially as herein described.

3. A flexible metallic tubing comprising a series of convolutions of a strip of metal, Which tubing has a polygonal section formed by flattened surfaces arranged around the circumference of the tubing, and spirally to the axis thereof, the strip of meta] having both of its lateral margins bent in reverse directions parallel to the axis of the tubing and respectively opposite the outer and inner surfaces of the strip so as to form interlocking channels for contiguous convolutions; substantially as described.

4. A flexible metallic tubing comprising a series of convolutions of a strip of metal, Which tubing has a polygonal section formed by flattened surfaces arranged around the circumference of the tubing, and spirally to the axis thereof, the strip of metal having both of its lateral margins bent in reverse directions parallel to the axis of the tubing and respectively opposite the outer and inner surfaces of the strip so as to form interlocking channels for contiguous convolutions and complete channeled corrugations intermediate of the said interlocking channels; substantially as described.

In testimony whereof We have signed our names to this specification in the presence of tWo subscribing Witnesses.

WILLIAM BERRYMAN. CHARLES CAMUS.

lVit-nesses J osnrrr MILLARD, WV. J. SKERTEN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

1 Washington, D. G. 

